package com.guaju.yueshangLife.utils;

import android.util.Base64;


import com.guaju.yueshangLife.net.ApiService;

import java.security.MessageDigest;
import java.security.spec.AlgorithmParameterSpec;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

/**
 * Created by chunlei.lu on 17/5/9.
 */

public class AESCrypt {

    private final Cipher cipher;
    private final SecretKeySpec key;
    private AlgorithmParameterSpec spec;
    //    public static final String SEED_16_CHARACTER = "U1MjU1M0FDOUZ.Qz";
    public static final String SEED_16_CHARACTER = ApiService.SMS_KEY;
    public static final String USER_CENTER_POST_KEY = "74730175e132fa15";
    public static final String USER_CENTER_GET_KEY = "e2dceedcc37b810d";


    public AESCrypt() throws Exception {
        // hash password with SHA-256 and crop the output to 128-bit for key
        MessageDigest digest = MessageDigest.getInstance("SHA-256");
        digest.update(SEED_16_CHARACTER.getBytes("UTF-8"));
        byte[] keyBytes = new byte[32];
        System.arraycopy(digest.digest(), 0, keyBytes, 0, keyBytes.length);
        cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
        key = new SecretKeySpec(keyBytes, "AES");
        spec = getIV();
    }

    public AESCrypt(String secret_key) throws Exception {
        // hash password with SHA-256 and crop the output to 128-bit for key
        MessageDigest digest = MessageDigest.getInstance("SHA-256");
        digest.update(secret_key.getBytes("UTF-8"));
        byte[] keyBytes = new byte[32];
        System.arraycopy(digest.digest(), 0, keyBytes, 0, keyBytes.length);
        cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
        key = new SecretKeySpec(keyBytes, "AES");
        spec = getIV();
    }

    public AlgorithmParameterSpec getIV() {
        byte[] iv = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,};
        IvParameterSpec ivParameterSpec;
        ivParameterSpec = new IvParameterSpec(iv);
        return ivParameterSpec;
    }

    public String encrypt(String plainText) throws Exception {
        cipher.init(Cipher.ENCRYPT_MODE, key, spec);
        byte[] encrypted = cipher.doFinal(plainText.getBytes("UTF-8"));
        String encryptedText = new String(Base64.encode(encrypted,
                Base64.DEFAULT), "UTF-8");
        return encryptedText;
    }

    public String decrypt(String cryptedText) throws Exception {
        cipher.init(Cipher.DECRYPT_MODE, key, spec);
        byte[] bytes = Base64.decode(cryptedText, Base64.DEFAULT);
        byte[] decrypted = cipher.doFinal(bytes);
        String decryptedText = new String(decrypted, "UTF-8");
        return decryptedText;
    }

}
